PORTSMOUTH — The center lift span of the Memorial Bridge will be floated down river, set in place and tested during the five-day period between 9 a.m. June 10 and 9 a.m. June 15, according to Archer Western Contractors (AWC).

The United States Coast Guard (USCG) has issued a river closure during that time period to allow AWC full access to the bridge span and ensure the safety of construction workers and all waterway users.

The USCG notice states, “The Coast Guard will enforce a Regulated Navigation Area (RNA) that encompasses all navigable waters on the Piscataqua River, surface to bottom, in the vicinity of the Memorial Bride construction zone. The RNA is effective within a 300-yard radius of position 43 degrees 04' 46” N, 70 degrees 45' 10” W, in between Portsmouth and Badgers Island in Kittery, Maine.”

It goes on to explain that, “Heavy lift operations are sensitive to water movement, and wake from passing vessels could pose significant risk of injury or death to construction workers.”

Similar to the three-day closure in February 2012 that took place when the old bridge's center span was removed, this closure agreement was developed as part of the bridge construction permit issued by the USCG to NHDOT in 2011.

According to Steve DelGrosso, AWC project manager, setting the center span in place is a much longer process that setting the north and south spans in place. “This is a much more complex process,” he said, listing just some of the tasks that need to be completed. “We will be working 24 hours a day for the duration of the 5-day channel closure. The temporary jacking towers on the barge Cape Cod need to be dismantled so that the barge can be removed from the channel. There are 64 counterweight wire rope connections in a tight configuration to make up and adjust. The operating wire ropes will be connected and adjusted. The machine rooms under the ends of the center span are complex, and completing the electrical connections to the towers will be time consuming. Once all connections are made, final adjustments need to be completed to more closely balance the counterweights with the span.” He went on to day that AWC would be making every effort to complete the installation and lifting of the center span in as little time as possible, but he anticipates needing the full five days.

The center span is the final span of the three to be set in place, and signals the beginning of the home stretch for opening the bridge to traffic, which will take place sometime in July. The exact schedule for opening will not be available until a few weeks prior to the date.